Fluoride is a critical weapon in the war against tooth decay. But this natural chemical proven to strengthen tooth enamel has also aroused suspicion over the years that it might cause health problems.

These suspicions have led to rigorous testing of fluoride's safety. And the verdict from decades of research? We've found only one verifiable side effect, a condition called enamel fluorosis. Caused by too much fluoride present in the body, enamel fluorosis produces white streaks and patches on teeth, and can develop into darker staining and pitting in extreme cases. But other than having an unattractive appearance, the teeth remain sound and healthy.

Fortunately, you can reduce the risk of fluorosis by limiting fluoride exposure to within recommended limits. Fluoride can show up in processed foods and other substances, but the two sources you should focus on most are oral hygiene products and fluoridated drinking water.

Dentists highly recommend using toothpaste with fluoride to fight tooth decay. But be careful how much your family uses, especially younger members. An infant only needs a slight smear of toothpaste on their brush for effective hygiene. At around age 2, you can increase the amount to about the size of a vegetable pea.

As to drinking water, most utilities add fluoride to their supply. If yours does, you can find out how much they add by calling them or visiting cdc.gov ("My Water's Fluoride"), where you can also learn more about recommended levels of fluoridation. If you think it's excessive, you can switch to water labeled "de-ionized," "purified," "demineralized," or "distilled," which contain little to no added fluoride.

Even if your fluoridated water is within recommended levels, you may wish to take extra precautions for infants nursing with formula. If possible, use "ready-to-feed" formula, which usually contains very low amounts of fluoride if any. If you're using the powdered form, use only water with the aforementioned labeling for mixing.

Before making any drastic changes that might affect your family's fluoride intake, consult with your dentist first. And be sure you're keeping up regular dental visits—your dentist may be able to detect any early signs of fluorosis before it becomes a bigger problem.